Shouldn't a kitchen 'fridge be on it's own circuit?

I thought major appliances like refrigerators in newer houses were supposed to be on dedicated circuits.

I just replaced a melted outlet in my kitchen. It was a 15 amp outlet, wired as a pass-through using the screw terminals. The outlet says “For 15A branch circuits only”. (The breaker on this circuit is 20A)

The same circuit powers the fridge, 2 outlets in the kitchen (one of which powers a toaster), a couple of outlets in the laundry room, and outlet on the floor in the kitchen. I haven’t traced the wiring for certain but I’m pretty sure the fridge and toaster outlets pass through the outlet that melted.

I replaced the outlet and re-wired it using pig-tails rather than pass-through, but if the outlet says “For 15A branch circuits only” that sure sounds to me like it’s not rated to be anywhere on a 20A circuit.

So my questions are 2:

Should a house built in 2000 in Fairfax county, Virginia have a large refrigerator on a shared circuit? (It was built to order by a supposedly well-regarded builder.)

Is there any way it’s ok to have an outlet that says “For 15A branch circuits only” wired into a 20A circuit? Somebody on another thread here said something like “All 15A outlets are rated for 20A pass-through” but an outlet that is explicitly labeled as only for 15A circuits sure seems like it doesn’t belong on a 20A circuit.